Question: We live in a land in which the sun does not set until 21:30 (09:30pm) or 22:00 (10:00pm), so when should we break our fast?
Response: Break your fast when the sun has set. So long as you have a night and day in 24 hours, it is obligatory that you fast even if the day is long.
Shaykh Ibn ‘Uthaymeen
Fataawa Ramadhaan – Volume 1, Page 212, Fatwa No.155